Ford or applicable 300-400 cfm carbs? Need listing.

I'm currently trying to compile a list (hopefully I can get one from the junkyard instead of paying $300 I didn't plan on..) of carburetors I can use on my 223 Ford hop-up. From a general rule of 1.5*CID I got like 334 cfm, though I know it's more complex than that, clifford seemed to recommend a 390 cfm holley, and someone on fordsix.com mentioned using a 500 cfm (seems a little high...) jetted down way low that seemed to work. BTW, i'm fairly high elevation too.

Any help on this would be appreciated.
thanks